Electron microscopy of tobacco mosaic virus under conditions of minimal beam exposure

New Approaches to the Detection of Microbial Plant Pathogens

“…This is the method of choice when presented with a plant sample with suspected viral infection. Since biological objects are readily destroyed when exposed to the electron beam, a method of ensuring minimum exposure to the region of interest, until ready for photographing, has been devised (Williams and Fisher, 1970) and refined recently (Wrigley, Brown and ChiIlingworth, 1983). This is important for the identification of virus-like particles (VLP) amongst the cell debris.…”

Three-dimensional Structure of a Type III Glutamine Synthetase by Single-particle Reconstruction

“…Images were recorded by the minimum dose technique (Williams & Fisher 1970) programmed using the TVIPS software (Tietz, 1986;EM-MENU 2003), to reduce the exposure to damaging radiation. During the focussing stage of this procedure, astigmatism and defocus were corrected by inspection of the real time power spectra calculated from the images.…”

Retrospective on the early development of cryoelectron microscopy of macromolecules and a prospective on opportunities for the future

“…What was needed was a method for maintaining protein crystal hydration in the high vacuum of the microscope. Microscopes at that time had the capability of resolving features as fine as the polypeptide chain, but such structures could not be seen in early negative stain micrographs, even with the application of low dose techniques (Williams and Fisher, 1970). The vision of using the electron microscope for protein structure determination would remain unrealized unless the native order present in a protein crystal could be preserved.…”